Emergency mine elevator

ABSTRACT

An emergency escape hoist assembly installed adjacent a mine shaft. The assembly has a cage and associated hoist mechanism normally parked in a retracted position relative to the mine shaft. The cage and hoist mechanism can be operated from pushbutton switches either at the mine level, at the hoist or at ground level. When the cage is called, a main power unit is energized and the cage and hoist mechanism are moved so as to position the cage over the shaft. The cage then descends and stops at the mine level. Personnel board the cage and push the hoist button, causing the cage to ascend. The cage stops at ground level and then the entire unit returns to its normal parked position. The mechanism is controlled by limit switches with necessary electrical and hydraulic interlocks to assure proper sequence of operations.

sates atent 11 1 11 1 3,757,701

Lepley et a1. Sept. 11, 1973 1 EMERGENCY MINE ELEVATOR 3,341,034 9/1967Blasen 214 95 Rx Inventors: Russell L. p y, 511 East Green 3,390,6577/1968 Schneider 212/6 X Werner Motyl 247 Primary ExaminerEvon C. BlunkOglevee Ln., both of Connellsvdle, Assistant Exammer-Merle F. Maffel Pa.15425 Attorney-Hyman Berman et al. [22] Filed: Oct. 22, 1971 21 AppL1510.: 191,762 [57] ABSTRACT 7 An emergency escape hoist assemblyinstalled adjacent a mine shaft. The assembly has a cage and associated[52] US. Cl. 104/242, 104/154, 212/5, hoist mechanism normally parked ina retracted posi 187/67 tion relative to the mine shaft. The cage andhoist [5 Cl. mechanism can be operated from p h Switches [58] Fm d ofSearch I 9 either at the mine level, at the hoist or at ground level.212/5 214/95 IDs/127 165; When the cage is called, a main power unit isenergized 104/ 154 and the cage and hoist mechanism are moved so as toposition the cage over the shaft. The cage then de- [56] References cuedscends and stops at the mine level. Personnel board the UNITED STATESPATENTS cage and push the hoist button, causing the cage to as- 463,95911/1891 Van Vradenburg 105/127 cend. The cage stops at ground level andthen the en- 688,601 12/1901 Dean 187/67 tire unit returns to its normalparked position. The 360,347 1907 Beechefm 104/247 mechanism iscontrolled by limit switches with necesg lf t 3 sary electrical andhydraulic interlocks to assure proper 1n y 3,123,240 3/1964 MacAlpine187/96 x Sequence of operauons' 3,159,110 12/1964 Wylie 105/165 X 10Claims, 13 Drawing Figures Patented Sept. 11, 1973 3,757,701

6 Sheets-Sheet INYEX '11 ms 5 P052954 4 .4 4 5 4 5% 4 pa e/v5? a M0 7Y4,- 40 1 11 amanosucv MINE ELEVATOR This invention relates to emergencyescape devices, and more particularly to an emergency elevator device toallow personnel to escape from a mine shaft under emergency conditions.

A main object of the invention is to provide a novel and improvedemergency escape elevator device to permit miners or other personnel toescape from a mine under emergency conditions, the escape device beingrelatively simple in construction, being arranged so that it is normallyin a non-obstructing relationship with respect to its associated mineshaft, and being operable to automatically move into working positionwhen its use is required.

A further object of the invention is to provide an improved automaticemergency escape elevator assembly which is normally positioned besideor near a mine shaft and which, when called, will move over the mineshaft, lower a cage to the mine bottom and stop to allow personnel toboard the cage, after which such personnel can again energize theapparatus so as to cause it to raise the cage and the personnel thereinto the surface, after which the apparatus returns to a retractedposition.

A further object of the invention is to provide an improved automaticemergency escape hoist apparatus for a mine, the apparatus combining thefeatures of automatic horizontal mobility and vertical hoisting inproper sequence without requiring the use of an attendant or operator,the apparatus involving inexpensive components, being relatively compactin size, being reliable in operation, and providing a means for therapid escape of personnel from a mine under emergency conditions.

A still further object of the invention is to provide an improvedemergency mine escape elevator device which is installed beside or neara mine shaft, and which is arranged so that no portion thereof isnormally over the mine shaft, whereby the apparatus is not normally inthe path of possible explosive forces, and thus, in its normal position,is not subject to damage and will not be rendered inoperative andunuseable by the sudden occurrence of emergency conditions causingexplosions, or the like A still further object of the invention is toprovide an improved automatic emergency escape apparatus providing ameans of escape for personnel from a mine shaft, the apparatus employinga unique arrangement of components providing a high degree ofreliability of operation and employing automatic control elements whichaccurately limit the movement of the parts thereof in a manner toprovide a high degree of safety in operation and rapid action thereofwhen called upon under emergency conditions.

A still further object of the invention is to provide an improvedemergency mine elevator employing an escape cage which is normallylocated in a retracted position relative to the associated mine shaftand which is moved to an overlying position with respect to the shaftwhen the device is placed in operation, the apparatus being providedwith safety stop means to insure against over-travel when the cage ismoved over the mine shaft, which is provided with means to preventpossible tipping or overturning of the cage during operation, and whichis further provided with means to control the gravitational and otherforces developed thereby so as 2 to give a high degree of stability tothe apparatus and to make it safe to operate.

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein:

FIG. I is a vertical cross-sectional view taken through the groundadjacent a mine shaft and showing a typical improved emergency mineelevator assembly according to the present invention, the parts thereofbeing shown in parked positions.

FIG. 2 is a vertical cross-sectional view similar to FIG. I, but showingthe parts of the emergency elevator apparatus in operated position withits cage lowered to mine level.

FIG. 3 is an enlarged cross-sectional view taken substantially on theline 3-3 of FIG. 2.

FIG. 4 is a longitudinal vertical cross-sectional view takensubstantially on the line 4-4 of FIG. 3.

FIG. 5 is an enlarged fragmentary vertical crosssectional view takensubstantially on the line 55 of FIG. 4.

FIG. 6 is an enlarged fragmentary elevational view of the cage memberemployed in the emergency mine elevator assembly of FIGS. 1 to 5.

FIG. 7 is a horizontal cross-sectional view taken substantially on theline 7-7 of FIG. 6.

FIG. 8 is a bottom plan view of the cage member taken substantially onthe line 8-8 of FIG. 6.

FIG. 9 is a fragmentary vertical cross-sectional view takensubstantially on the line 99 of FIG. 6.

FIG. 10 is a schematic diagram showing the hydraulic circuit of theemergency mine elevator apparatus illustrated in FIGS. l to 9.

FIG. 11 is a block diagram schematically indicating the electricalcircuit connections of the electrically operated components of thesystem illustrated in FIG. 10, as employed in the emergency mineelevator apparatus of FIGS. I to 9.

FIG. 12 is a schematic block diagram showing the general layout of theelectrical components of FIG. 1 1.

FIG. 13 is a schematic block diagram, generally similar to FIG. I2, butshowing the schematic layout of components in a modification of thepresent invention wherein the apparatus employs only electricalcomponents instead of employing the hydraulic components of FIG. 12.

Referring to the drawings, 1 1 generally designates an improvedemergency mine elevator assembly constructed in accordance with thepresent invention. The assembly III is illustrated as a typicalinstallation adjacent to the vertical shaft portion 12 of a mine, forexample, of a mine wherein said vertical shaft portion communicates withat least one horizontal bottom shaft portion J13 in the mannerillustrated in FIG. 2. The elevator assembly 11 is mounted on a suitablehorizontal supporting plate or slab 14 located adjacent to and extendinglaterally from the top rim of the vertical mine shaft portion 12.

Mounted on the supporting slab 14 are the parallel guide rails 15, 15extending for the length of the slab 14 and terminating adjacent thevertical mine shaft portion 12. Upstanding stop blocks 16, 16 aresecured on the rails 15, 15 adjacent the rim of the vertical shaftportion 12, as shown in FIGS. 1, 2, 3 and 4. Designated at 17 is aplatform member provided with conventional supporting wheels Id whichengage on the rails 15 and thereby support the platform I7 forhorizontal movement, for example, for movement from a retracted positionrelative to the vertical mine shaft portion 12, to an extended positionsuch as that shown in FIG. 2. Thus, the platform 17 may be normally inthe retracted position thereof shown in FIG. 1, but may be extended, ina manner presently to be described, to the position thereof shown inFIG. 2, wherein the leftward supporting wheels 18 engage the stop blocks16.

Mounted on the slab 14 midway between the rails 15, at the right portionthereof, as viewed in FIGS. 3 and 4, is an upstanding longitudinallyextending I-beam 19 which is suitably anchored to the slab l4 and whichis employed as a safety hold-down beam to retain platform 17 in ahorizontal position. Thus, said platform is provided with a pair ofdepending opposing, substantially L-shaped members 20, 20 whosehorizontal arms engage slidably beneath the opposite margins of the topflange of the I-beam l9 and constrain the platform 17 to move in ahorizontal direction, as is apparent from FIG. 5.

Designated at 21 is an elongated cylinder which has one end thereofconnected to a depending abutment member 23 carried by platform 17 andhas a piston provided with a piston rod 63 extending from the oppositeend of the cylinder and connected to an upstanding block 22 secured tothe slab 14. The cylinder 21 may be of substantial length so that itspiston has a rather long stroke, for example, of the order of 8 feet.Thus, the cylinder 21 is employed as the means for retracting andextending the platform 17 horizontally in a manner presently to bedescribed.

Rigidly secured to the left end of the platform 17, as viewed in FIGS. 1to 4, is an upstanding frame-like enclosure 24 which extends verticallyupwardly from the plane of platform 17 and which is suitably braced, forexample, by inclined strut members 25 and suitable horizontal tie bars26, as shown in FIG. 4. Thus, the upstanding vertical frame-likeenclosure 24 is rigidly secured to the platform 17 and is braced so thatit has an axis perpendicular to the plane of the platform.

Mounted on the right end portion of platform 17, as viewed in FIGS. 1 to4, is a housing 27 containing a hoist assembly 28 which may be of aconventional type having a hydraulic driving motor 29 which is drivinglyconnected to a cable reel 30 and which is provided with a hydraulicallyoperated brake assembly 31. The housing 27 also contains a conventionalhydraulic power unit 32 which may comprise a pump 33 driven by anelectric motor 34, and which may include a suitable reservoir 35 forhydraulic fluid, as well as other necessary components of a conventionalhydraulic power unit. Thus, as shown in FIG. 10, the unit may include anelectrically energized heater 36 immersed in the reservoir 35, andvarious other conventional components presently to be described.

The hoist reel 30 has wound thereon a hoist cable 37 which engages overa pulley 38 journaled on the top of the upstanding frame-like enclosure24 and has its end suitably secured to the top end of an elevator cage39 normally contained within the frame-like enclosure 24, as illustratedin FIG. 4.

As shown in FIGS. 1, 2 and 4, the lower portion of the frame-likeenclosure 24 is provided with suitable wire mesh or chain link panels 40on all of the sides thereof with the exception of the side openingtoward the platform 17.

As shown in FIGS. 6 to 9, the cage 39 comprises a generally cylindricalframework having top and bottom main structural sections shown at 41 and42. Thus, the bottom section 42 comprises a circular band 43 having adiametral cross bar 44 of I-beam shape and having additional cross barelements of I-beam shape 45 extending perpendicular to the diametralcross bar 44 and rigidly connecting said cross bar to the circular band43. Rigidly secured on the frame elements 43, 44 and 45 is a circularfloor plate 46. Secured to the bottom surfaces of the bar members 45 arerespective square plates 47, located adjacent the outer band 43, asshown in FIG. 8, and secured to each plate 47 is a depending bufferspring 48, said springs 48 serving as cushioning elements for cushioningthe bottom ends of the travel of the cage 39 when it descends to thelevel of the horizontal mine shaft portion 13, as will be presentlydescribed.

The upper cage frame section 41 is generally similar to the lower framesection 42 and comprises a circular band 49 provided with a pair ofparallel spaced, substantially diametrally extending channel bars 50, 50arranged in the manner illustrated in FIGS. 7 and 9, namely, with theirwebs parallel and spaced apart in the manner illustrated in FIG. 9. Therespective channel members 50 are rigidly connected to the circularouter band 49 by I-beams 51 extending perpendicular to the channelmembers 50 and having rigid connections at their end, for example, bywelding, or the like, with band 49 and channel members 50.

The cable 37 is provided at its end with an eye bracket 52 through whichextends a horizontal bolt member 53 connecting the webs of the channelmembers 50, 50 at the intermediate portions thereof, as shown in FIGS. 6and 9, providing a pivotal connection of member 52 to the top framestructure 41. A bracket member 63 is clamped to the cable 37 asubstantial distance above the connector 52 and respective stabilizingchains 54, 54 connect opposite lugs 55, 55 of bracket 63 with respectivehorizontal bolts 56 extending through the webs of the channel members50, 50 symmetrically located on opposite sides of the cable fasteningbolt 53.

The top and bottom frame sections 41 and 42 are rigidly connected by aplurality of vertical cage bars 57 which are provided with upwardly andinwardly inclined top extensions 58 whose top ends are rigidly connectedwith a circular band 59 at the top end of the cage. As shown in FIG. 8,the members 57 may be of channel shape and are preferably arranged withtheir flanges directed outwardly. Any desired number of vertical members57 may be employed, for example, six equally spaced members in thetypical design illustrated in the drawings. The intermediate portions ofthe vertical cage bars 57 are rigidly connected to a circular rail band60 with one portion thereof between a pair of vertical cage bars 57being cut off to define a doorway, and a chain 61 being employed as aclosure for such doorway, the chain having at least one detachable endto allow access into and out of the cage.

The vertical frame-like enclosure 24 is suitably formed to define adoorway 62 which is registrable with the doorway of the cage when thecage is in its elevated position, for example, the position thereofshown in FIGS. 3 and 4, to allow the occupants of the cage to emergetherefrom onto the platform 17.

As above described, the wheel stops 16 are located so as to position theenclosure 24 over the vertical mine shaft portion 12 when the platformis moved to its extended position, namely, the position thereof shown inFIGS. 2, 3 and 4. In the normal position of the apparatus, for example,that shown in FIG. 1, the cage structure 39 is supported substantiallyentirely within the enclosure 24, and at a sufficient height to clearslab 14, so that it may be freely moved to its operating position,namely, the position of FIG. 2 when the platform is extended. As will befurther apparent from FIG. 1, the cage 39 is supported at a sufficientheight so that it not only clears the slab 14, but also the partscarried by and projecting upwardly from said slab, as well as the toprim of the casing of the vertical mine shaft portion 12.

The apparatus also includes a main control cabinet 66, which may belocated at any convenient position, for example, in the hoist housing27, and which serves as a means to furnish controlled energization tothe various electrical components of the apparatus as well as a junctionbox for making the necessary electrical connections between the sourceof electrical power and the various components of the apparatus.

It will be noted that the vertical frame bars 57 and their upwardlyconvergent extensions 58 define skid members which will slide along thewall of the vertical mine shaft portion 12, and are smoothly engageablewith said wall to prevent hang-ups during hoisting. The upwardlyconvergent top end elements 58 permit easy entry of the cage into thehoist tower frame 24. The buffer springs 46, provided at the bottom ofthe cage, absorb shocks when the cage reaches the level of thehorizontal mine shaft portion 13. The cable 37 is preferably of anon-spin type so as to give a controlled ride under emergencyconditions.

As will be preferably explained, the hoist drum 30 is provided withbraking means including an emergency brake drum 64 directly fastened tothe reel drum 30. The braking mechanism is controlled by a hydrauliccylinder 66, with means to automatically apply the brake when the hoistis stopped. The hydraulic hoist motor 29 may be of the direct gear type,coupled to the hoist reel by flexible coupling means 67. The hoistingspeed and cycle areautomatically controlled by a conventional hoistcontrol 168 having a tly ball speed governor 169 and a gear driven camwheel 64 which controls acceleration, deceleration, stopping and timefor each portion of the cycle. As will be presently explained,electrical interlocks with the valves controlling the hydraulic motorinsure proper operation.

As will be apparent from FIGS. 1, 2 and d, the hoist tower or enclosure26 is of sufficient height to completely contain the cage assembly 39and to provide for a reasonable amount of over-travel thereof.

Referring now to FIG, 10, it will be seen that the outlet of the pump 33is connected to a hydraulic line 66 connected through respectiveconventional reversing valve assemblies 69 and 76 to the hoist motor 29and to the cage positioning cylinder 21, The reversing valve assembly 69has respectiveoperating solenoids A and B. When solenoid B is energized,the valve assembly 69 operatesto provide downward movement of the hoistcage, and conversely, when solenoid A is energized, the valve assemblyoperates to provide for upward movement of the hoist cage. Thus, thevalve assembly 69 controls the direction of flow of hydraulicfluid inthe circuit containing the hydraulic motor 29. Similarly,

the cylinder control valve assembly 711 has respective operatingsolenoids E and l to control the direction of hydraulic fluid furnishedto the circuit containing the cylinder 21. When solenoid F is energized,the valve assembly 79 operates to cause the cylinder 21 and platform 1'7to be moved to the position of FIG. 2, and conversely, when solenoid Eis energized, the valve assembly causes retraction of platform 17 to theposition of 1.

The hydraulic circuit containing the cylinder 21 is provided withrespective conventional flow control valve devices 71 and 72 utilizingto control the speed of movement of the cylinder 21, piston rod 63, andtherefore, the speed of extension and retraction of the cage assembly. Aconventional reducing valve assembly 73 is provided in the connectionbetween pressure line 66 and valve assembly which may be adjusted toallow the hydraulic circuit of the cylinder 21 to operate at lower thansystem pressure, inasmuch as full system pressure will not be requiredfor the operation of cylinder 21.

The hydraulic circuit containing the hoist motor 29 is provided withdual relief valves 74 and 75, with replenishing check valves 76 and 77,as shown in FIG. 10. This fluid circuit also contains a conventionalholding counterbalance valve '78 and includes a control valve 79 havingan operating solenoid S. The valve 79 has connected thereacross aconventional choke block flow control valve-device 80 acting as apressure compensating device.

A conventional relief valve 81 is connected between hydraulic line 68and reservoir 35, and a dump valve 82 is connected between valve 81 andthe reservoir, said valve 82 being provided with the operating solenoidV. The valve arrangement including the relief valve 81 and the dumpvalve 82 is of a conventional type and is such that when the hydrauliclines 83 and 84 leading respectively to the reversing valve assemblies69 and 7 0 are blocked, the pressure fluid from line 68 will return toreservoir 35. Energization of valve solenoid V will block return throughdump valve 82.

A dump valve 85 is also connected to line 68 through a conventional flowcontrol device 86, the dump valve 85 having the operating solenoid D.Fluid pressure line 34 is connected to the brake cylinder 66 through abranch circuit 63 including a speed-controlling reducing valve 69, acheck valve 911, a brake control valve assembly 91 and a further speedcontrolling valve device 92. The valve assembly 91 has an operatingsolenoid K. As shown, the valve assembly 91 normally connects cylinder66 to the reservoir, and under these conditions braking force is appliedto drum 64'. In order to release such braking force, solenoid K must beenergized, to allow pressure fluid to flow to cylinder 66.

As is diagrammatically illustrated in FIG. 11, energization of thevarious solenoids is provided from a suitable power supply source andconventional wiring in the control cabinet 64. Respective push buttonswitch assemblies 95, 96 and 97 are provided for controlling theoperation of the system. Push button switch assembly 96 is located in aconveniently accessible location in the housing 27. Push button switchassembly 96 is located at ground level on the frame-like enclosure 24 ata position conveniently accessible to occupants of the cage 39 when saidcage is in its elevated position, such as that shown in FIG. 4. Pushbutton switch assembly 97 is located at the horizontal mine shaftportion 13 adjacent the landing position of cage 39 when it hascompleted its downward travel.

Conventional circuitry is provided, not shown, for energizing solenoidsV and F responsive to actuation of one of the push buttons, for example,lower push button of any one of the push button assemblies 95, 96 or 97.Thus, for example, the lower push button is shown at 101 for the hoistpush button assembly 95. The other push button assemblies 96 and 97 havecorresponding lower push buttons. Said assemblies also have hoist pushbuttons 102 which are employed to elevate the cage 39, in a mannerpresently to be described.

Thus, as above described, with the motor 34 energized, actuation of anyof the push buttons 101 causes energization of solenoids V and F,causing cylinder 21 to be extended, namely, to move to the position ofFIG. 2, moving the tower 24 over the vertical mine shaft 12. When thecylinder 21 reaches its limit of travel, it operates a limit switch 93which causes solenoid F to become deenergized and causes solenoids B andS to become energized, solenoid V remaining energized, to start downwardmovement of the hoist. The choke block device 80 connected across valve79 is adjustable to allow adjustment of acceleration of the hoist eitherdown or up.

It will be understood that when the hoist motor 29 becomes energized,the brake cylinder 66 simultaneously receives pressure hydraulic fluid,by the energization of the solenoid K. Braking action is controlled bythe provision of respective on and off limit switches 98 and 99 whichare employed in a conventional manner to provide an electrical interlockbetween the brake and motor control solenoids.

As above mentioned, when the tower 24 reaches the position of FIG. 2,the solenoids B and S are energized to cause motor 29 to be operated ina direction to lower the cage 39. The cage descends, tripping a slowdown" limit switch 106 which is suitably wired so as to deenergizesolenoid S and energize solenoid D, to start slow down by controlledflow out of the motor by way of pressure-compensated flow control device86.

When the cage 39 reaches its bottom limiting position, it actuates alimit switch 107 which is suitably wired so as to deenergize solenoid B,and after a time delay to deenergize solenoids V and D. The cage 39 isthus stopped in its lowered position, for loading.

Suitable wiring is provided so that when any one of the "hoist pushbuttons 102-is actuated, solenoids V, A and S are energized, causing themotor 29 to be activated in a direction to raise the cage 39. As thecage 39 approaches its uppermost position, it trips a limit switch 108which is wired so that its activation energizes solenoid D, to therebydeny flow of pressure hydraulic fluid to the motor 29. An upper limitswitch 109 is provided, being engageable by the cage 39 as it reachesits landing position in tower 24. Limit switch 109 is suitably wired soas to deenergize solenoid A responsive to actuation thereof, and after atime delay to deenergize solenoids V, S and D. Thus, as the cage 39rises and approaches its top limit of travel, it slows down by trippingthe "slow down" limit switch 108, and thereafter is stopped in its toplanding position by actuating the top limit switch 109. As will beapparent from FIG. 10, the deenergization of solenoids A and S cut offfluid flow in the motor circuit and deenergization of the solenoids Dand V cause the output flow from the pump 33 to be returned to thereservoir through the relief valve 81.

Suitable circuitry is provided for energizing solenoids E and V when thecage 39 is in its upper landing posi tion, whereby to retract theplatform 17 from the position of FIG. 2 to the position of FIG. 1. Thus,a suitable control switch may be provided for energizing solenoids E andV at this time, whereby to return platform 17 to its starting position,shown in FIG. 1. This circuit is further controlled by a limit switch94, engageable by suitable means, for example, a projection on cylinder21, so as to deenergize solenoids E and V at the end of the retractionstroke.

As above mentioned, at the completion of the escape operation, thesolenoids E and V are energized to retract the platform 17 to thenon-operating position thereof shown in FIG. 1. This may be done by theprovision of a suitable energizing circuit which can be controlledmanually, for example, by a push button switch, connected to thesolenoids E and V. This circuit may include the limit switch 94,-whichis arranged to be actuated responsive to the completion of theretraction movement of the cylinder 21, for example, by employing aprojection on the cylinder to actuate said limit switch. Thus, the limitswitch 94 operates to deenergize the solenoids E and V at the end of theretraction movement of platform 17 in substantially the same manner inwhich solenoid F becomes deenergized by the actuation of limit switch 93at the completion of the forward movement of cylinder 21, except that inthis case the solenoid V remains energized and the solenoids D and Sbecome energized.

In the alternative form of the invention illustrated in FIG. 13,electric power means is used to operate the various parts of theapparatus. Thus, an electric motor 21 is attached to the platform 17 inany suitable manner, the shaft of the motor 21' being provided with apinion gear 201 which meshes with a rack bar 202 secured to the fixedslab 14. The rack bar 202extends in the direction of intended movementof the platform 17, the platform being supported on rails 15, as in thepreviously described form of the invention and being provided withretaining means 19, 20, as previously described. The hoist drum 28 isdriven by a reversible electric motor 29' energized through the maincontrol unit 64' and being reversibly operable through circuitscontrolled by the lower push buttons 101 and the hoist push buttons 102,providing reversible operation of motor 29' similar to reversibleoperation of the hydraulic motor 29 provided in the previously describedform of the invention.

The energizing circuits for the motor 21 are controlled by respectivelimit switches 93 and 94 so that motor 21' becomes deenergizedautomatically by the actuation of limit switch 93 by suitable abutmentmeans on platform 17 when the platform reaches its forward limit oftravel, and similarly, when electric motor 21 is energized forretracting the platform it becomes deenergized by the engagement ofsuitable abutment means on platform 17 with the limit switch 94 when theplatform reaches the end of its retracted path of travel. The rack bar202 may be fastened to any suitable portion of the stationary structurebeneath the platform 17, for example, to the retaining beam member 19.

The hoist motor 29' may be automatically deenergized at the limits oftravel of the cage 39, for example,

by the provision of suitable limit switches 10% and I09 located to slowdown and deenergize the hoist motor 29' when it approaches ground level,and by other limit switches, not shown, similar to the limit switches11% and 107 of the previously described embodiments of the inventionlocated adjacent the lower limit of travel of the cage 39 and arrangedto be actuated thereby as the cage approaches and finally reaches itslower limit of travel, namely, reaches the horizontal mine shaft portion13. The hoist drum 28 is provided with suitable braking meansinterlocked with the motor 29' in a conventional manner. Thus, the drum28 may be provided with an emergency brake drum 204 engaged by a brakeband 205 whose tension is controlled by a solenoid 206 whose plunger isconnected to the brake band 205 for applying braking force to the brakeband and whose limits of travel are controlled in a conventional mannerby the provision of limit switches 98 and 99' com nected in the circuitof the braking solenoid 206.

The mode of operation of the embodiment shown in FIG. 13 is generallysimilar to that of the previously described form of the invention, themotor 21 being energizedin a direction to move the platform 17 to theposition of FIG. 2 responsive to the actuation of any one of the lowerpush buttons. The motor 21 is automatically deenergized when it reachesthe position of FIG. 2 and the motor 29 becomes energized in a directionto lower the cage 39, becoming denergized when the cage has reached itslowermost position, such as that shown in FIG. 2. When a hoist pushbuttom 102 is actuated, motor 29 becomes energized in a direction toraise the cage and automatically becomes deenergized by the action oflimit switches I08 and 109 to position the cage at its upper limit oftravel, for example, that shown in FIG. 4. Subsequently, motor 21 may beenergized to retract platform 17 to its original nonoperating position,such as that shown in FIG. 1.

It will be understood that within the spirit of the present inventionany conventional hoist assembly, either hydraulically driven or drivenby an electric motor, may be employed to raise and lower the passengercage. Also, within the spirit of the present invention, thishydraulically or electrically powered hoist assembly may be employed inconjunction with either the hydraulically operated platform-shiftingmeans shown in FIGS. 1 to 12 or with the electrically powered platformshifting means shown in FIG. 13.

While certain specific embodiments of an improved emergency mineelevator have been disclosed in the foregoing description, it will beunderstood that various modifications within the spirit of the inventionmay occur to those skilled in the art. Therefore, it is intended that nolimitations be placed on the invention except as defined by the scope ofthe appended claims.

What is claimed is:

I. In combination with a mine shaft having a top opening, a slab-likehorizontal support on the ground adjacent said top opening and extendinglaterally therefrom away from said opening, platform means movablymounted on said support, a hoist assembly mounted on said platformmeans, said hoist assembly having a passenger car and including means tolower and raise said passenger car, said platform means being movablehorizontally toward and away from said opening on said support from aretracted position wherein said passenger car is not in verticalregistry with said top opening to an extended position wherein saidpassenger car overlies 'said top opening, stop means limiting saidplatform means to said extended position, an upstanding block on saidsupport adjacent said top opening, and a horizontal hydraulic cylinderand piston assembly connected between said platform means and saidupstanding block for moving the platform means horizontally back andforth toward and away from said opening between said retracted andextended positions, wherein said horizontal hydraulic cylinder andpiston assembly comprises a horizontal hydraulic cylinder connected tosaid platform means and containing a piston having a piston rodconnected to said upstanding block, a source of hydraulic fluid, andconduit means including an electrically operated reversing valveconnecting said source to the opposite ends of said cylinder, andwherein said cylinder has a projection thereon and said reversing valvehas a platform-extending solenoid and a platform-retracting solenoid forselectively operating the valve to admit hydraulic fluid to one or theother of said opposite ends, means to energize the platformextendingsolenoid, a first limit switch engageable by said projection todeenergize the platform-extending solenoid substantially when saidplatform means reaches said extended position, means to energize saidplatform-retracting solenoid, and a second limit switch engageable bysaid projection to deenergize said platform-retracting solenoid whensaid platform means reaches said retracted position.

2. The structure combination of claim I, and wherein said support isprovided with a pair of guide rails extending horizontally from said topopening and said platform means has wheels journalled thereto andsupportingly engaged on said guide rails, an upstanding I- beam securedon said support substantially midway between and parallel to said guiderails, and a pair of depending opposing substantially L-shaped memberssecured to said support means adjacent the connection of the cylinderthereto and engaging slidably beneath the opposite margins of the topflange of said I-beam, whereby to constrain said platform means to movein a horizontal direction.

3. The structural combination of claim 1, and wherein said conduit meansis provided with respective flow control valves between said reversingvalve and the respective opposite ends of the cylinder.

4. The structural combination of claim 2, and wherein said stop meanscomprises an upstanding block element on said support engageable by oneof said wheels when the platform means is in said extended position.

5. The structural combination of claim 4, and wherein said last-namedblock element is located adjacent said top opening.

6. The structural combination of claim 5, and wherein said platformmeans is provided with an upstanding vertically extending frame-likeenclosure located to receive said passenger car when the car is in itselevated position.

7. The structural combination of claim 6, and wherein saidpassengercarcomprises a vertical cage having a plurality of external verticalskids spaced around its periphery, saidskids being at times slidablyengageable with the wall of the mine shaft.

b. The structural combination of claim 7, and wherein said skids haveinwardly convergent top ends, whereby the cage has an upwardly taperingconfigura- 1 1 12 tion to facilitate entry of the cage into theframe-like 10. The structural combination of claim 9, and deenclosurewhen the cage is being elevated therein. pending resilient bumper meanssecured to the bottom 9. The structural combination of claim 8, and ofsaid cage to cushion descent of said cage to a lowwherein said skids arechannel-shaped in cross-section ered position in the mine shaft. andhave outwardly directed flanges. 5

1. In combination with a mine shaft having a top opening, a slab-likehorizontal support on the ground adjacent said top opening and extendinglaterally therefrom away from said opening, platform means movablymounted on said support, a hoist assembly mounted on said platformmeans, said hoist assembly having a passenger car and including means tolower and raise said passenger car, said platform means being movablehorizontally toward and away from said opening on said support from aretracted position wherein said passenger car is not in verticalregistry with said top opening to an extended position wherein saidpassenger car overlies said top opening, stop means limiting saidplatform means to said extended position, an upstanding block on saidsupport adjacent said top opening, and a horizontal hydraulic cylinderand piston assembly connected between said platform means and saidupstanding block for moving the platform means horizontally back andforth toward and away from said opening between said retracted andextended positions, wherein said horizontal hydraulic cylinder andpiston assembly comprises a horizontal hydraulic cylinder connected tosaid platform means and containing a piston having a piston rodconnected to said upstanding block, a source of hydraulic fluid, andconduit means including an electrically operated reversing valveconnecting said source to the opposite ends of said cylinder, andwherein said cylinder has a projection thereon and said reversing valvehas a platform-extending solenoid and a platform-retracting solenoid forselectively operating the valve to admit hydraulic fluid to one or theother of said opposite ends, means to energize the platform-extendingsolenoid, a first limit switch engageable by said projection todeenergize the platformextending solenoid substantially when saidplatform means reaches said extended position, means to energize saidplatformretracting solenoid, and a second limit switch engageable bysaid projection to deenergize said platform-retracting solenoid whensaid platform means reaches said retracted position.
 2. The structurecombination of claim 1, and wherein said support is provided with a pairof guide rails extending horizontally from said top opening and saidplatform means has wheels journalled thereto and supportingly engaged onsaid guide rails, an upstanding I-beam secured on said supportsubstantially midway between and parallel to said guide rails, and apair of depending opposing substantially L-shaped members secured tosaid support means adjacent the connection of the cylinder thereto andengaging slidably beneath the opposite margins of the top flange of saidI-beam, whereby to constrain said platform means to move in a horizontaldirection.
 3. The structural combination of claim 1, and wherein saidconduit means is provided with respective flow control valves betweensaid reversing valve and the respective opposite ends of the cylinder.4. The structural combination of claim 2, and wherein said stop meanscomprises an upstanding block element on said support engageable by oneof said wheels when the platform means is in said extended position. 5.The structural combination of claim 4, and wherein said last-named blockelement is located adjacent said top opening.
 6. The structuralcombination of claim 5, and wherein said platform means is provided withan upstanding vertically extending frame-like enclosure located toreceive said passenger car when the car is in its elevated position. 7.The structural combination of claim 6, and wherein said passenger carcomprises a vertical cage having a plurality of external vertical skidsspaced around its periphery, said skids being at times slidablyengageable with the wall of the mine sHaft.
 8. The structuralcombination of claim 7, and wherein said skids have inwardly convergenttop ends, whereby the cage has an upwardly tapering configuration tofacilitate entry of the cage into the frame-like enclosure when the cageis being elevated therein.
 9. The structural combination of claim 8, andwherein said skids are channel-shaped in cross-section and haveoutwardly directed flanges.
 10. The structural combination of claim 9,and depending resilient bumper means secured to the bottom of said cageto cushion descent of said cage to a lowered position in the mine shaft.